package com.fengju.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.fengju.reggie.common.BaseContext;
import com.fengju.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Locale;

/**
 * 检查用户是否完成登录
 */
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {

    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse resp = (HttpServletResponse) response;

        //获取本次请求的URI
        String requestURI = req.getRequestURI();

        log.info("拦截到请求: {}", requestURI);

        //定义不需要处理的请求路径
        String[] urls = new String[] {
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login",
                "/doc.html",
                "/webjars/**",
                "/swagger-resources",
                "/v2/api-docs"
        };

        //判断本次请求是否需要处理
        boolean check = check(urls, requestURI);

        //无需处理则放行
        if(check) {
            log.info("本次请求{}不需要处理", requestURI);
            chain.doFilter(req, resp);
            return;
        }

        //1.判断用户状态
        Long empId = (Long) req.getSession().getAttribute("employee");
        if(empId != null) {
            log.info("用户已登录，用户id为：{}", empId);
            BaseContext.setCurrentId(empId);
            chain.doFilter(req, resp);
            return;
        }

        //2.判断用户状态
        Long userId = (Long) req.getSession().getAttribute("user");
        if(userId != null) {
            log.info("用户已登录，用户id为：{}", userId);
            BaseContext.setCurrentId(userId);
            chain.doFilter(req, resp);
            return;
        }

        log.info("用户未登录");
        //未登录则返回未登录结果，通过输出流的方式向客户端响应数据
        resp.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;

    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if(match) {
                return true;
            }
        }
        return false;
    }

}
